The present invention relates to an elongated nozzle assembly for closing and/or regulating the discharge from a metallurgical vessel of molten metal in the form of a wide strip. More particularly, the present invention relates to such an assembly including refractory tubular stator and rotor members assembled together so that the rotor member is rotatable relative to the stator member in a molten metal-tight manner. The rotor and stator members have therethrough discharge openings in the form of slots elongated in the direction of the longitudinal axes of the members, such that upon rotation of the rotor member relative to the stator member, the discharge opening of the rotor member may be brought into and out of alignment with the discharge opening of the stator member, thereby closing and/or regulating the discharge of the molten metal through the nozzle assembly.
An elongated nozzle assembly is disclosed in German DE 38 05 071 A1 wherein each of the rotor and stator members has elongated discharge openings but also elongated inlet openings. The inlet and discharge openings are positioned diametrically opposite each other in each of the members, relative to the coincident longitudinal axes of the two members. When the assembly is in its open position, the molten metal flows radially through the elongated inlet openings in the two members, then radially through the internal cavity of the inner member, and radially through the elongated discharge openings in the two members. The internal cavity within the inner member does not itself contribute to the distribution of the molten metal via the elongated discharge openings. Additionally, the fact that each member has therein two elongated openings tends to weaken the structure of each of the members and thereby the structure of the nozzle assembly.
German DE 38 09 071 A1 describes a nozzle assembly wherein the need for two elongated openings in the rotor member that is positioned as the inner member is avoided. A recess in the rotor member forms a connecting channel between an inlet opening and a discharge opening in the outer, stator member. However, in this arrangement it also is necessary for the outer member to have two elongated openings. Also, the cavity within the inner member does not contribute to the distribution of the melt to the discharge opening. The recess is positioned relatively free to the sealing surface of the outer member as a result of which it is subject to wear by the molten metal.
Additionally, German DE 35 08 218 A discloses a control element for a slotted nozzle wherein the flow of molten metal is adjusted by regulating the viscosity of the molten metal by heat. A stopping or closing element is not shown.
Swiss CH 671,716 discloses a device for pouring or discharging thin strips or foils of metal wherein a tubular nozzle body is provided with an elongated slot. One face of the nozzle body is closed, and molten metal flows in through another face of the nozzle body. To control the discharge of the molten metal, the level of the molten metal in the metallurgical vessel is controlled, or the molten metal is maintained under pressure when the nozzle body is arranged above the level of the molten metal. The nozzle body does not form a closing and/or regulating mechanism.